2018 MERCEDES-BENZ CLA COUPE ECU

Tires
Display messagesPossible causes/consequencesand MSolutions
CheckTirePressureSoonCanad aonly:
The tire pressure loss warning system hasd etecte das ignificant loss
in pressure.
Aw arning tone also sounds.
Possibl ecauses:
Ryouh avec hange dthe positions of the wheels and tire sorinstalled
new wheels and tires
Rthe tire pressure in one or mor etiresh asdropped
GWARNING
Tire pressures thata retoo lo wposet he following hazards:
Rtheym ayburst, especially as the load and vehicl espeed increase.
Rtheym aywear excessivel yand/or unevenly, which mayg reatly
impai rtire traction.
Rthe drivin gcharacteristics, as well as steerin gand braking ,maybe
greatl yimpaired.
There is ariskofana ccident.
XStop the vehicl ewithou tmaking any sudden steerin gorbraking
maneuvers. Pa yattentio ntothe trafficc onditions as yo udoso.
XSecure the vehicl eagain st rolling away (Ypage 141).
XCheck the tire sand,ifn ecessary,f ollowthe instructions for aflat
tire (Ypage 271).
XCheck the tire pressures and ,ifnecessary,c orrect the tire pressure.
XRestart the tire pressure loss warning system when the tire pres-
sure is correct (Ypage 294).
CheckTirePressureThenRestartR unFlatIndicator
Canadaonly:
The tire pressure loss warning system generated adisplay message
and hasn ot been restarted since.
XSet the correct tire pressure in al lfou rtires.
XRestart the tire pressure loss warning system (Ypage 294).
Run FlatI ndicatorInoperativeCanadaonly:
The tire pressure loss warning system is faulty.
XVisitaq ualified specialis tworkshop.
PleaseCorrectTirePressureUSA only:
The tire pressure is too lo winatleastone of the tires, or the tire
pressure differenc ebetween the wheels is too great.
XCheck the tire pressures at the next opportunity (Ypage 294).
XIf necessary,c orrect the tire pressure.
XRestart the tire pressure monitor (Ypage 297).
Displaymessages211
On-boardc omputer andd isplays
Z

Display messagesPossible causes/consequences andMSolutions
Check TiresUSAo nly:
The tire pressur einoneor mor etires has dropped significantly. The
whee lposition appear sinthemultifunction display.
Aw arning tone also sounds.
GWARNIN G
Tir ep ressures that are to olow pos ethe followin ghazards :
Rthey may burst, especially as th eload and vehicl espeed increase.
Rthey may wear excessivel yand/o runevenly, whic hmay greatl y
impair tire traction .
Rthed rivin gcharacteristics ,aswell as steering and braking ,may be
greatl yimpaired.
There is ariskofana ccident.
XStop thevehicl ewithout making any sudden steering or braking
maneuvers .Pay attention to th etraffic condition sasyou do so.
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XChec kthe tires and ,ifneces sary, follow th einstruction sfor aflat
tire (Ypage 271).
XChec kthe tire pressur e(Ypage 294).
XIf necessary, correc tthe tire pressure.
Warnin gTireM al‐functionUS Ao nly:
The tire pressur einoneor mor etires has dropped suddenly. The whee l
position appear sinthemultifunction display.
GWARNIN G
Drivin gwithaf lat tire poses ariskoft hefollowin ghazards :
Raflat tire affects th eabilit ytos teer or brak ethe vehicl e
Ryou could lose control of th evehicl e
Rcontinued drivin gwithaf lat tire will caus eexces sive heat build-up
and possibl yafire
There is ariskofana ccident.
XStop thevehicl ewithout making any sudden steering or braking
maneuvers .Pay attention to th etraffic condition sasyou do so.
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XChec kthe tires and ,ifneces sary, follow th einstruction sfor aflat
tire (Ypage 271).
TirePress.Monito rCurrently Unavaila‐ble
USAo nly:
Becaus ethere is interferenc efromas tron gs ource of radi owaves, no
signals from th etirep ressur esensor sare detected. The tire pressur e
monitor is temporarily malfunctioning .
XDrive on.
The tire pressur emonitor restarts automatically as soo nasthe
problem has been resolved.
212Display messages
On-boardc omputer andd isplays

Display messagesPossible causes/consequences andMSolutions
TransmissionNotinPRiskofV ehicleRollin gAway
The driver's door is open or no tfull yc losed and th etransmission is in
position R,N or D.
Aw arning tone also sounds.
GWARNIN G
The vehicl emay rol laway.
There is ariskofana ccident.
XShift thetransmission to position P.
XSecurethe vehicl eagainst rollin gaway (Ypage 141).
XClosethe driver's door completely.
Servic eRequiredDoNot Shift GearsVisit Dealer
You canno tchang et he transmission position due to amalfunction .
Aw arning tone also sounds.
If transmission position Dis selected:
XDrive to aqualified specialist workshop without shifting th etrans -
mission from position D.
If transmission position R,N or Pis selected:
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XNotify aqualified specialist workshop or breakdown service.
Onl yShift to 'P'whenVehicl eisSta‐tionar y
The vehicl eismoving.
XPull ove rand stop th evehicl esafely as soo naspossible, payin g
attention to roa dand traffic conditions.
XShift th etransmission to position P.
To Engage Trans‐miss. PositionRFirst DepresstheBrake
You hav eattempte dtoshift from position Dor Nto transmission
position R.
XShift th etransmission to position Rwhile depressing th ebrak e
pedal .
ReversingNotPossi‐bleServic eRequiredThe automatic transmission is malfunctioning .You canno tbacku p.
XVisit aqualified specialist workshop .
Transmission Mal‐functionThe automatic transmission is malfunctioning .
XVisitaqualified specialist workshop .
Transmission Mal‐function StopThe automatic transmission is malfunctioning .
XPull overand stop th evehicl esafely as soo naspossible, payin g
attention to roa dand traffic conditions.
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XConsult aqualified specialist workshop .
214Display messages
On-boardcomputer andd isplays

Display messagesPossible causes/consequences andMSolutions
StopVehicl eShifttoPLeave EngineRunnin g
The automatic transmission has overheated.
XDrive on carefully.
The automatic transmission is available again when th edisplay
message goe sout.
If th emultifunction display still shows th edisplay message :
XPull overand stop th evehicl esafely as soo naspossible, payin g
attention to roa dand traffic conditions.
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XWait until th eautomatic transmission has cooled down and th edis-
play message has disappeared.
Auxiliary Batter yMalfunctionThe auxiliary battery for th eautomatic transmission is no longer bein g
charged.
XVisit aqualified specialist workshop .
XUntilthen, set th etransmission to position Pbefore you switch off
th ee ngine.
XBefor eleaving th evehicle, apply th eelectric parking brake.
Trans. Oil Overhea‐ted Drive on wit hCare
Mercedes-AMG vehicles: th etransmission oil has overheated.
Manual drive progra mM and th etem porarily active manual drive pro -
gra ma re no longer available. The engin epowe routput is reduced.
XAllow th evehicl etoc ooldown .
4matic CurrentlyUnavailable4MATIC has overheated. The vehicl eisonlyd riven by th efront wheels.
XDrive on .
The airflow cools 4MATIC mor equickly.
Whe nthe display message goe sout,4 MATIC is available again and
th ev ehicl eisd riven by all fou rwheels.
4matic Inoperative4MATIC is malfunctioning .The vehicl eisonlyd riven by th efront
wheels.
XVisit aqualified specialist workshop .
NThe trunk lid is open.
XClosethe trunk lid.
MThe hoo disopen.
Aw arning tone also sounds.
GWARNIN G
The open hoo dmay bloc kyour vie wwhen th evehicl eisinm otion.
There is ariskofana ccident.
XPull overand stop th evehicl esafely as soo naspossible, payin g
attention to roa dand traffic conditions.
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XClosethe hood.
Display messages215
On-boardc omputer andd isplays
Z

Display messagesPossible causes/consequences andMSolutions
Â
ObtainaNew Key
The SmartKey needs to be replaced.
XVisit aqualified specialist workshop .
Â
ReplaceKey Batter y
The SmartKey battery is discharged.
XChange thebattery (Ypage 73) .
Â
Don't Forget You rKey
The display message is shown for amaximum of 60 seconds and is
only areminder.
You hav eopened th edriver's door wit hthe engin eswitched off .The
SmartKey is no tintheignition lock. Awarning tone sounds.
XTakethe SmartKey wit hyou when you leav ethe vehicle.
Â
Key Not Detected(redd isplay message )
The SmartKey is no tinthevehicle.
Aw arning tone also sounds.
If th eengineiss witched off ,you can no longer loc kthe vehicl ecen-
trally or start th eengine.
XPull ove rand stop th evehicl esafely as soo naspossible, payin g
attention to roa dand traffic conditions.
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XLocate th eSmartKey.
Becaus ethe re is interferenc efromas tron gs ource of radi owaves, th e
SmartKey is no tdetecte dwhilstthe engin eisrunning.
Aw arning tone also sounds.
XPull ove rand stop th evehicl esafely as soo naspossible, payin g
attention to roa dand traffic conditions.
XSecur ethe vehicl eagainst rollin gaway (Ypage 141).
XInser tthe SmartKey int othe ignition loc kand drive in SmartKey
mode.
Â
Key Not Detected(whit edisplay message )
The SmartKey is currentl yundetected.
XChange th elocation of th eSmartKey in th evehicle.
If th eSmartKey still canno tbedetected:
XOperat ethe vehicl ewitht he SmartKey in th eignition lock.
Â
Remove 'Start 'But‐ton and Insert Key
The SmartKey is continually undetected.
The SmartKey detection function has atem porar ymalfunction or is
faulty. Awarning tone also sounds.
XInser tthe SmartKey int othe ignition loc kand tur nittot hedesire d
position .
XVisitaqualified specialist workshop .
Display messages217
On-boardc omputer andd isplays
Z

Warning and indicator lamps in the instrument cluster
General notes
Some systems carry outaself-diagnosis when the ignition is switched on. Therefore, some indicator
and warning lamps may light up or flas htemporarily .This behavior is non-critical.
These indicator and warning lamps only indicate amalfunction if they light up or flas hafter starting
the engine or whilst driving.
Safety
Seat belts
Warning/
indicator
lampNSignal type
Possiblec auses/consequence sand M
Solutions
üNAfter engine start, the red seatb eltwarning lam plights up for six seconds.
The seatb eltwarning lam preminds the drivera nd front passenger to fasten their
seatb elts.
XFasten you rseatb elt(Ypage44).
üNAfter starting the engine, the red seatb eltwarning lam plights up. In addition, a
warning tone sound sfor up to six seconds.
The driver's seatb eltisnot fastened.
XFasten you rseatb elt(Ypage44).
The warning tone ceases.
üN The red seatb eltwarning lam plights up after the engine starts, as soon as the
driver's or the front-passenger door is closed.
The driverorf ront passenger has not fastened their seatb elt.
XFasten yourseatb elt(Ypage44).
The warning lam pgoes out.
There are objects on the front-passenger seat.
XRemove the objects from the front-passenger seata nd stow them inasecure
place.
The warning lam pgoes out.
üNThe red seatb eltwarning lam pflashes and an intermittent audible warning
sounds.
The driverorf ront passenger has not fastened their seatb elt. The vehicleisbeing
drivenf aster than 15 mph (25 km/h )orhas briefly been drivenf aster than 15 mph
(25 km/h).
XFasten you rseatb elt(Ypage44).
The warning lam pgoes out and the intermittent warning tone ceases.
There are objects on the front-passenger seat. The vehicleisb eing drivenfaster
than 15 mph (25 km/h )orhas briefly been drivenf aster than 15 mph (25 km/h).
XRemove the objects from the front-passenger seata nd stow them inasecure
place.
The warning lam pgoes out and the intermittent warning tone ceases.
218Warning and indicator lamps in the instrument cluster
On-board computer and displays

Safety systems
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
$JN$ (USA only), J(Canada only): the red brake system warning lamp is lit
while the engine is running. Awarning tone also sounds.
GWARNING
The brake boosting effect is malfunctioning and the braking characteristics may be
affected.
There is arisk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehicle against rolling away (Ypage 141).
XConsult aqualified specialist workshop.
XObserve the additional display messages in the multifunction display.
$JN$ (USA only), J(Canada only): the red brake system warning lamp is lit
while the engine is running. Awarning tone also sounds.
There is not enough brake fluid in the brake fluid reservoir.
GWARNING
The braking effect may be impaired.
There is arisk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehicle against rolling away (Ypage 141).
XDo not add brake fluid. Adding more will not correct the malfunction.
XConsult aqualified specialist workshop.
XObserve the additional display messages in the multifunction display.
Warning and indicator lamp sinthe instrument cluster219
On-board computer and displays
Z

Warning/
indicator
lampNSignal type
Possiblec auses/consequences and M
Solutions
æNThe yellow reserve fuel warning lamp flashes while the vehicleisinm otion.
In addition, the ;Check Engine warning lamp may light up.
The fuel filler cap is not closed correctly or the fuel system is leaking.
XCheck that the fuel filler cap is correctly closed.
XIf the fuel filler cap is not correctly closed: close the fuel filler cap.
XIf the fuel filler cap is closed:visitaqualified specialist workshop.
?NThe red coolant warning lamp lights up while the engine is running and the
coolant temperature gage is at the start of the scale.
The temperature sensor for the coolant temperature gauge is malfunctioning.
The coolant temperature is no longer being monitored.T here isarisk of engine
damage if the coolant temperature is too high.
XPul lover and stop the vehicles afelyand switch off the engine, paying attention
to road and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehiclea gainst rolling away(Ypage141).
XConsult aqualified specialist workshop.
Warning and indicator lamps in the instrument cluster225
On-board computer and displays
Z